Free amino acid composition and botanical origin of honey

The main amino acids found in 31 Spanish honeys of five different single botanical origins, were proline, phenylalanine, tyrosine and lysine, followed by arginine, glutamic acid, histidine and valine. Principal component analysis explained 64% of the variance with the first three PC variables, the lavender honeys being the only group well differentiated. Although the best grouped honeys were those from orange blossom, overlapping with eucalyptus honeys, on the one hand, and with the indistinguishable group formed by rosemary and thyme honeys, on the other hand, was observed. The Student–Newman–Keuls test allowed the grouping of rosemary, thyme and orange blossom honeys, whereas eucalyptus and lavender honeys showed specific amino acid compositions which made them different when compared with this group and also between themselves. Lavender honeys had the highest concentrations of tyrosine. The results obtained for the former honeys together with those obtained for another set of 17 samples, were used to establish a range for amino acid composition of Spanish honeys.